Epinephrine, also known as 4-[(1R)-1-Hydroxy-2-(methylamino)ethyl]-1,2-benzenediol, is the active principle of the adrenal medulla and an endogenous catecholamine which acts directly on both alpha and beta adrenergic receptors. When used in pharmaceutical compositions, epinephrine can act as a non-selective alpha and beta adrenergic agonist and can work rapidly to improve breathing, stimulate the heart, raise dropping blood pressure, reverse hives, and reduce swelling of the face, lips, and throat. Uses for epinephrine include emergency treatment of allergic reactions (Type 1), including anaphylaxis, induction and maintenance of mydriasis during intraocular surgery, treatment of bronchospasm, sensitivity reactions, cardiac arrhythmias, GI and renal hemorrhage, superficial bleeding, premature labor, hypoglycemia, and cardiogenic, hemorrhagic, and traumatic shock. Epinephrine can also be used to increase blood flow in ACLS during CPR, as an adjunct to local anesthesia, and for radiographic uses.
One example of a pharmaceutical composition with epinephrine as an active agent is Adrenalin®, a sympathomimetic agent manufactured and distributed by Par Sterile Products, LLC. Adrenalin® is an epinephrine injection suitable for subcutaneous, intracameral, and intramuscular administration. When diluted, it may also be administered as ophthalmic irrigation or intracameral injection. Adrenalin® is used primarily as an emergency treatment of allergic reactions (Type 1), including anaphylaxis, and for induction and maintenance of mydriasis during intraocular surgery.
Adrenalin® is a clear, colorless solution containing 1 mg/mL epinephrine in a clear glass vial. Adrenalin® is currently available in 1 mL single-dose and 30 mL multi-dose formulations. For the 1 mL product, each 1 mL of Adrenalin® contains 1 mg epinephrine, 9.0 mg sodium chloride, 1.0 mg sodium metabisulfite, hydrochloric acid to adjust pH, and water for injection. For the 30 mL product, each 1 mL of Adrenalin® solution contains 1 mg epinephrine, 9.0 mg sodium chloride, 1.5 mg sodium metabisulfite, hydrochloric acid to adjust pH, 5.4 mg chlorobutanol as a preservative and water for injection. The pH range of Adrenalin® is 2.2-5.0.
Adrenalin® 1 mL is FDA approved for an 18 month shelf life. The Adrenalin® 30 mL product is approved for an even shorter shelf life of 14 months. Shelf life is limited by the formation of degradants, which mainly comprise epinephrine sulfonic acid (ESA) and D-epinephrine, an enantiomer of L-epinephrine that has insignificant therapeutic activity. The currently approved Adrenalin® 1 mL product has a total impurity limit of ≤20%. Adrenalin® 1 mL has a concentration limit of ≤13.5% ESA and ≤9.5% D-epinephrine. The currently approved Adrenalin® 30 mL product has a total impurity limit of ≤20%. Adrenalin®30 mL has a concentration limit of ≤14.5% ESA and ≤9.5% D-epinephrine.
There is currently a need in the art for improved epinephrine-containing pharmaceuticals. It is an object of the present invention to provide an epinephrine-containing pharmaceutical composition that addresses some of the limitations of present formulations.